List Comprehension equivalent

[Jerry via Digitalmars-d-learn]

On Friday, 17 March 2017 at 17:13:48 UTC, Russel Winder wrote:
> I have a bit of code:
>
> 	string[] returnValue;
> 	foreach(string key, string[] value; groups) {
> 		returnValue ~= 
> value.sort!debianPackageNumberComparator()[0..$-1].array;
> 	}
> 	return returnValue;
>
> [...]

You forgot a ! on the map call.

.map!((Tuple!(string, string[]) a) => 
a[1].sort!debianPackageNumberComparator()[0..$-1])